


Honesty

by 0neType



Category: Undertale (Video Game)
Genre: Dry Humping, First Times, Inexperience, M/M, Sensitive bones, ages aren't specified, but be warned that they're both under 18, first heat
Language: English
Status: Completed
Published: 2016-08-30
Updated: 2016-08-30
Packaged: 2018-08-12 01:42:51
Rating: Mature
Warnings: Underage
Chapters: 1
Words: 3,850
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7915585
Author URL: https://archiveofourown.org/users/0neType/pseuds/0neType
Summary: <blockquote class="userstuff">
              <p>He’s panting hard, body burning with the remnants of a dream that’s too hazy to properly remember. Even now his body feels too hot, too heavy and his first thought is that it’s because he and Sans fell asleep bundled up together to stave off the cold.</p>
            </blockquote>





	Honesty

**Author's Note:**

> this doc is saved in my writing folder as "baby's first heat fic" hahaaaaaa

Papyrus is sweltering.

He’s panting hard, just barely waking up, body burning with the remnants of a dream that’s too hazy to properly remember. He vaguely recalls figures in his mind, shadowy and nondescript. They had been almost incorporeal but had moved over him with a force that was solid and firm, pushing and tugging and _lingering_ over his body while he lay helpless at their mercy.

It was the sort of powerlessness that would frighten him normally but, tonight, the images make him burn in a way that’s entirely unfamiliar.

Even now his body feels too hot, too heavy and his first thought is that it’s because he and Sans fell asleep bundled up together to stave off the cold. Waterfall isn’t exactly the most frigid place—nothing, his brother had warned, like the town that they’re heading to—but there’s still enough chill to incapacitate monsters as malnourished as them without the proper precautions. The easiest and most effective way to fight off the brisk nights was simply sharing space with each other while they slept.

A quick glance to his side however, reminds him that that is not the case.

His brother is lying at a distance from him, arms splayed out above his head as he sleeps.

He’d had another fight with Sans yesterday. Shouting and hissing at each other even when they were supposed to be trying to lay low for fear of hidden assailants waiting to for a chance to pounce. They seemed to be arguing more and more lately and Papyrus felt anger simmer in his soul at just at the thought.

If only Sans would just _listen_ to him.

It had been yet another case of Sans babying him, treating him like he was still some sort of child to be protected. Never mind the fact that Papyrus is hardly all that younger than him. Never mind that he’s more than capable of handling things himself after having years of practice being on the run together.

Never mind that, with every day that passes, the more exhausted Sans seems to get.

Papyrus _hates_ seeing him like that; tired and weary, looking for all the world like he hasn’t slept a day in his life. He wants to help. Wants to share the burden so that his brother won’t have to struggle so much.

But Sans just never seems to understand.

In the aftermath of yesterday’s dissension, Sans had laid out the meager bedding they owned side-by-side, like he did every night. But, this time, Papyrus had refused to get anywhere near him. Instead, he pointedly lay a few feet off from his brother on the bare stone floor of their tiny, sequestered cave.

He must have dozed off sometime later. Whenever he had, it was probably earlier than Sans if the warm jacket now covering his frame had anything to say about it. His brother must have laid it over him while he slept.

There’s an awful pang in his soul as he flexes his phalanges in the worn tufts of fur along the hood. The heated feeling in his bones pulses even stronger as he grips tight into the fabric. He glances back off to the side, frowns at his brother’s lax, peaceful face.

Sans is so _stupid_.

Always ready to give everything he has but too stubborn to accept the same in return.

There’s a blossoming of something sickly warm in his soul at the thought and Papyrus gives a startled gasp, clenching harder at his brother’s coat. He grits his teeth as a sudden wave of warmth washes over his body, leaving him tingling and flushed. He shifts, uncomfortable, and sits up when the pounding heat in his bones becomes too much to handle.

He pushes the jacket off of him but still the burning doesn’t fade. Instead, an electric chill pricks up along his spine and, underneath the dark of his shirt, Papyrus can make out the faint glow of his soul. He hesitates at the sight before cautiously lifting his top to inspect the aberration.

Exposing his bones to the cool night air is more jarring than he expects and he twitches reflexively as the chill bites into him. Still, he reaches a hand up carefully towards his ribcage only to hiss when a phalange makes contact with his sternum and the sensation pulses through him with a lingering weight. His soul shines even brighter at that, dazzling white on conspicuous display. 

He doesn’t dare touch it.

He now knows that there’s something seriously wrong with him.

There must be. That’s the only deduction that makes sense. Combined with the fever-like qualities he’s enduring and the strange shining of his soul, it’s an altogether unusual occurrence. He’s never even heard of something like this happening before.

As if to reinforce his discovery, his soul gives a bright pulse that rocks another heated sensation dragging through him and Papyrus chokes on the breath he’s been holding. He pants, short and ragged, eyes tearing up from some unknown strain his body is trapped under. He grips desperately into the shirt he still has pushed up, hunching forward as a low groan works its way past his clenched teeth.

“Papyrus?”

His soul lurches.

He shoots a look to his side and sees Sans sitting up, rubbing at his sockets even as his face affixes itself with a concerned frown. He hastily works his shirt back down, face burning in embarrassment. He feels like every one of his senses is on high alert, soul racing as his brother stares at him with a deep, searching gaze.

“What’s wrong?” Sans asks and, Papyrus doesn’t know why but, the sound of his voice—all rough and croaky from sleep—makes the burning in his body tingle slowly up his spine.

“ _Nothing_.” He bites out, watching as his brother flinches at his tone.

He snaps his gaze away before his face can betray him and forces himself to settle back down onto the floor. He pulls Sans’ jacket back over his frame and squeezes his sockets shut. He hopes against all hope that Sans is still upset from their fight and that he’ll turn over and go back to sleep without checking on him.

He hears his brother shift. He tenses under the jacket.

After a moment, he senses someone looming over him.

Sans touches his forehead and Papyrus immediately slaps his hand away, “ _Don’t_.”

“Fuck, Pap,” Sans says, eyes wide with worry, “You’re burning up.”

Papyrus ignores him; ignores the prickling sensation along the surface of the bone where Sans had brushed his hand against him, “Go back to sleep.”

“If you have a fever we should—”

“I don’t have a fever.”

“Papyr—”

“I’m _fine_ , Sans!” He shouts and his brother falls silent.

He’s thankful for that at least. He doesn’t think he can take much more of this. Papyrus doesn’t know what it is but he’s feeling twitchy and shaky and Sans being so close to him isn’t helping in the slightest. He just wants Sans to leave him alone already.

And then he can try to… handle this somehow.

“… what’s that?”

Papyrus frowns at the hushed whisper from his brother and follows Sans’ wide, wide eyes back to the center of his chest. He stops. Stares.

His soul is shining brighter—bright enough to see clearly right through the thickness of his shirt. He raises a hand up shakily to the front of his sternum but doesn’t bring it any closer to his soul than that. Even with the fabric of his clothing to act as a barrier, he doesn’t want to touch it.

“Papyrus,” Sans says and, this time, his voice is stern, “Let me see.”

“N-no.” The protest comes weaker than he would like and Papyrus is surprised at himself. He doesn’t know what’s happening to him, doesn’t know how the simple command from his brother has his knees feeling weak or how the low press of his voice has him feeling like he’s about to collapse in on himself. He feels flush and warm and he feebly tries to pull back as Sans reaches out towards him.

“ _Papyrus_.”

He shivers, hot heat jolting like electricity through him at the sound of his name.

He drops his arms to his sides.

Sans wastes no time, lifting up his shirt and baring the piercing glow of his soul. He inhales sharply, “What the…?”

Shame floods through him as he sees the state of his soul.

It’s glistening, white and shiny, like a film of thick liquid has been poured over it. It’s steadily dripping too—not much, just a slow drip-drip as the seconds pass—but it’s enough to make it seem messy and filthy and _wrong_. Papyrus wants to wrench his shirt back down and hide away. He feels his face burn hotter. He doesn’t look up to see his brother’s expression.

Sans lets his shirt drop, brings up both his hands and grips firmly onto either of Papyrus’s shoulders. He tries not to shudder at that. Tries fiercely to ignore his body’s sudden longing to be touched elsewhere by those same solid hands.

He shakes the idea away, doesn’t know why he even thought of it in the first place.

“Pap, I need you to be honest with me,” Papyrus doesn’t interrupt, too entranced by the lure of his brother’s unyielding tone, “Are you hurting? Are you injured anywhere?”

“No.” He manages to say, though it comes strained and whispered.

Sans sighs, not quite relieved but relenting, “Alright… alright, okay, so then we can probably wait till morning to find a doctor. It’ll be safer to go out then and, if it’s not hurting you, it’s probably not—”

Sans lets go of him and Papyrus _whines_.

He freezes.

Sans freezes.

He immediately drops his gaze down at his feet, clenching his fists at his sides. He knows his face must be burning. He refuses to look up even as Sans takes a step closer to him.

“Pap… what…?”

“It hurts.” He blurts without thinking.

He doesn’t have to look up to hear the frown in his brother’s voice, “But… I thought you said…”

“It…” Papyrus swallows reflexively, a motion done to gather himself more than out of any real need, “It hurts when you’re not t-touching me.”

Silence follows his words.

He still doesn’t look up, determined to stare at the floor forever if that’s what he needs to do.

He reminds himself that he’s not really lying. While it doesn’t actually _hurt_ , it _does_ ache—aches in a way that Papyrus hadn’t even _known_ was there until Sans let go and he was forced bereft of his touch. He shudders, the pulsating warmth seeming more unbearable than ever as time goes on.

He jumps when Sans’ hands come back to hold at his shoulders. His head shoots up, eyes fixing onto his brother’s expression. Sans is looking a little off to the side, face glowing lightly red.

“This… helps?” He asks, unsure.

Papyrus doesn’t respond, can’t with how choked he suddenly feels. He sees his eyesight go blurry and is confused for a second when suddenly Sans pulls him flush against his chest, shushing him and holding him tight.

“Shit, Pap. Don’t… don’t cry,” He’s crying? When had he started crying? He feels overwhelmed with the knowledge, notices it now when hot, wet tears start rolling afresh down his cheekbones, “I’m here for you, okay?”

Sans is cool to the touch, body lining up perfectly against his. Papyrus wants to grab onto him tight, wants to never let go, but he can’t find the strength to even lift his arms. He settles for pressing in as close to his brother as he can, reveling in being surrounded by his presence.

“Tell me how I can help, Pap,” Sans soothes, hand rubbing up and down his clothed spine and unintentionally making Papyrus shiver, “Tell me what you want and I’ll do it.”

There’s only one thing he wants.

“Please,” He croaks, pressing his flushed, wet face into the front of his brother’s shirt, “Please touch me.”

The hand at his back stills, “I… don’t know what you mean, Papyrus.”

It doesn’t help that Papyrus doesn’t know what he means either.

All he knows is that it feels _better_ when Sans’ hands are on him. That the burning settles from a flashfire to a low simmer, like every touch of his brother’s bones against his are a salve that cools and heals him. He wants that. He wants the soft friction of Sans’ bones on his body.

But… he can’t seem to find the words to explain it.

He tries to back away from his brother. Sans pauses for a moment before releasing him from his embrace.

Papyrus looks up at him, hesitant and uncharacteristically shy. All his usual boldness seems to have left him in his moment of weakness. With shaky hands, he reaches down to the hem of his shirt, watches as Sans follows with his eyes. He carefully lifts it up, exposing his chest to the open air once more.

“Here,” He whispers and Sans drags his gaze back up at him, “T-touch me here.”

To his credit, Sans doesn’t need to be asked twice.

Despite the uncertainty lurking in his eyes, he moves up close once more, reaches out with a trembling hand to press it against the right side of Papyrus’s ribcage, “L-like this?”

Warm, warm heat floods through his body at the simple touch and Papyrus leans into it, squeezing his sockets shut and nodding frantically at his brother. He keeps his mouth clenched shut, frightened by the noises he feels building up inside him. He’s not sure how Sans would react to them. Not when he already seems so undecided with his actions.

Sans moves his hand to grip at his bottom-most rib, waits for a moment before he tentatively strokes it. Papyrus bites back another sound, body flushing from the attention. Sans continues unaware, firmer with his strokes now that he knows what to do, phalanges deftly running over his ribs, and Papyrus feels that ache from before go from torturous to exquisite in a way that he’s never felt. His legs are starting to feel weak again but to tell Sans to change positions would mean stopping him, would mean stopping _this_.

And Papyrus doesn’t think he ever wants to stop being touched.

Sans’ other hand comes to rest at his spine and Papyrus shivers from the proximity of it. He looks up at his brother, sees the focus in his eyes and feels the press of his right hand at his back as he unconsciously pulls him closer. Something heated begins to pool in his pelvis at the sight of Sans watching him like that, with so much attention and devotion. Papyrus ducks his head.

His soul pulses hotly in his chest, warm with affection and the effects of whatever else is happening to him.

Sans strokes his spine.

“Aah!” Papyrus shouts, too surprised to hold it back and his brother immediately stops.

“Fuck, what—shit, Paps, d-did I hurt you—?!”

Papyrus stares at him, face warm and body heavy. He tingles all over, feels incomplete without his brother’s hands on him. He swallows, “Again.”

“W-what?”

“Do it again,” He presses himself back towards his brother, takes the opportunity to gently press him down till he’s sitting on the floor and Papyrus is straddling him, staring straight at his rapidly reddening face, “ _Please_ , Sans. Please, please, do it again.”

Nervous and slow, Sans hands come back up to his chest and spine, “Is this…?”

His brother wraps his phalanges around his spine, rubs quickly up and down over his vertebrae and Papyrus feels like his soul might just explode from the contact.

“Ah—yes, yes, _please_ —Sans—!” He doesn’t hold back his voice this time, doesn’t even think of it. Can’t when the way Sans is touching him leaves little room for anything but strangled breaths and moans.

“P-Papyrus…” Sans sounds embarrassed but he doesn’t stop, twists his wrist at Papyrus’s spine and goes faster as Papyrus continues to beg for more.

“Sans, sans, _sans, sa_ — ** _nnh_** —!”

Unconsciously, Sans thrusts up against him and Papyrus bites down a low groan as his clothed pelvis rubs up against his brother’s. Sans shudders at the contact, hands faltering in their motion as a shiver runs through him. Papyrus wonders if maybe he’s contagious. If maybe the heat that has plagued him since the second he’d woken up is now slowly overtaking his brother as well.

He… doesn’t hate the thought of it.

If they go down, they’ll go together.

As it should be.

Maybe it’s the thought of Sans being afflicted the same as him that emboldens him. Maybe it’s just that all the touching has eased the fire in his bones somewhat. Whatever it is, Papyrus uses the rush of adrenaline suddenly coursing through him to push at his brother’s chest, knocking him backwards.

Sans’ back hits the floor with a thud and he grunts at the impact. Before he can speak, Papyrus climbs on top of him, legs spread on either side of his body. He grabs onto his brother’s arms and pins them above his head. Sans doesn’t struggle, merely tests the hold a little before staring up at him, confused.

Papyrus looks down at his brother. He marvels a little at how good Sans looks like this, pressed into the ground unresistant. He looks perfect; flushed and sweaty and out of breath. He wonders why it took him so long to notice.

They may argue and fight and disagree but Sans was his brother. Whenever Papyrus needed him, Sans would be there. Whatever he wanted, Sans would give it to him. All he ever needed to do was to ask.

Sans was _his_.

“I love you.” Papyrus blurts.

Sans flushes from the sincerity of his proclamation, trembles a little underneath him, “I-I love you too.”

“So then why don’t you ever let me help you.” He accuses.

“Pap,” Sans looks pained, wounded by his words, “I just don’t want you to get hurt. You’re still a—”

Papyrus pushes down with his hips and Sans yelps as their pelvises rub together. He tightens his grip on his brother’s arms and repeats the motion, revels in the moan he drags out from his brother’s parted mouth. He’s not sure what’s better—the delicious rub of friction as he ruts against Sans like he was made for this or the low, broken sounds his brother makes as he picks up the pace.

He leans forward, still thrusting, growls against the side of his brother’s skull, “I’m not a kid anymore, Sans.”

“P-papyrus…” Sans has his eyes shut tight and Papyrus stares at him for a second before leaning back over to clank their teeth together.

“I love you,” He repeats, inching closer to his brother in an effort to make it easier to roll his hips, “I want to help you.”

“Y-you don’t need to, Pap.”

“I want to,” He insists and when he thrusts again, this time both of them are moaning and Papyrus can feel something build up deep within him, making him groan and stutter, “I-I want to be there for you, like you’re there for me. I w-want to take care of you. I don’t want y-you to ever get hurt.”

“Ahnn, Papyrus…”

The hotness in his body seems to spread to every inch of his bones. It’s all-consuming, building higher and higher up at he grinds against his brother. He can feel his soul drip faster, wet enough to dampen the front of his shirt. Sans is panting underneath him and Papyrus wonders briefly why they’ve never thought of doing this before. Why they’ve restricted themselves to barely-there brushes when they could’ve had _this_ instead.

He wants to sink into the feeling, wants keep Sans pinned underneath him forever as they rock against each other like that’s the only thing that’s ever mattered.

“You’re _mine_ , Sans,” He gasps as the heat within him reaches a peak, pushes harder and faster at Sans even as his brother writhes beneath him, “You’re mine and I won’t ever let anyone touch you.”

He gives one final thrust and his body shudders with the relief of released tension. He can hear himself moan brokenly, his soul splattering its fluid against the confines of his clothes. It’s as if all the knotted pressure inside him comes undone all at once and Papyrus feels truly at ease for the first time in ages. He breathes, whole and fulfilled.

Sans is still tense, straining against him.

“Hahh, _Papyrus_ —Pap, please—”

He stares at his brother, still partially dazed. He considers him carefully, his face flushed and needy. Papyrus stops rocking. He’s never been one to pass up an opportunity when he sees it.

He grips tighter onto Sans’ hands, hard enough that he knows his fragile sibling will bruise, “Let me help.”

“Papyrus—”

“ _Sans_.”

Sans looks up at him, eyes wet and desperate as he twitches with need. A shiver runs up Papyrus’s spine at the expression on Sans’ face. It occurs to him, not for the first time tonight, that he really does love his brother.

“Okay, Pap,” Sans breathes, eyelights hazy even as he nods, “I-if that’s what you really want.”

Papyrus relaxes his grip, leans forward to reward his brother with a gentle press of a kiss, “It is.”

His pelvis feels too sensitive for any more rubbing so Papyrus improvises with his hand instead.

He grips both of Sans’ wrists in one hand and reaches down with the other to press at his brother, rubbing up and down with his palm. He alternates the motion by dragging his fingers across the fabric of Sans’ shorts, fingers catching in the clothed notches in his bones. It doesn’t take long before his brother is shuddering in much the same way as Papyrus was earlier, voice choked off into silence as the tension leaves his body.

“Better?” He asks as Sans relaxes underneath him.

“Mmnn…” His brother offers, muzzy and soft.

Satisfied, Papyrus clambers off of him and settles in against his side instead. He pulls Sans in close, wraps his arms tight around his brother. The heat in his body hasn’t dissipated entirely—he can still sense it lingering somewhere deep in his bones—but it’s been sated enough for the time being. He argues to himself that that’s why he needs to stay near Sans; he’ll need his brother if it happens again.

He's not quite sure what any of this was but it didn’t seem dangerous like he’d first thought. It’s inconvenient—sets his emotions running up in a maelstrom of sentiment he can’t control—but ultimately not a pressing issue. There are more important things that require his attention right now, such as the gentle sigh that spills from Sans as he turns to wrap his own arms around Papyrus.

He sinks into his brother’s embrace, soul pounding happily.

Further inspection will have to wait till morning.

**Author's Note:**

> And thus begins Pap's journey into becoming a dom and manipulating his brother through sex. gg pap ur a star


End file.
